The DB-90 can't send MIDI clock data, but it does respond to it. So it's similar to the M9 in that sense. If you want to sync everything together, you'll have to have something to generate a MIDI clock signal - something like this: http://www.kaom.com/...p/built_009.htm
The other issue is going to be how to split the MIDI signal, then. The M9 doesn't have a MIDI thru, so you're looking at another additional box - something like this: http://www.sweetwate...CFdBaMgodwBMAiA
So you'd take a MIDI cable from the MIDI clock pedal to the MIDI through box and then one cable from that to the DB-90 and another to the M9.
Personally, it seems like a lot of cabling and a lot of extra work to accomplish something relatively minor. I would probably say "forget it" and stick to tapping the beat in manually. As far the M9's looper, it doesn't have a quantize function, and there's no way to sync it to the tap tempo.
"It is not our duty to understand the arbitrary, meaningless dictates of machines"
- Don Norman in The Design of Everyday Things